luening



Sept. 29, 1925.

, 1,555,424 E. G. LUENING APPARATUS FOR THE PRODUCTION OF mmnoazu AND OXYGEN File i%2l, 1921 2 Sheets-Sheet l WI 0 I \l r 9 2 Zzya 72 qilzwrzzz YBY ArrmA/e'ra.

Sept. 29, 1925. 1,555,424

. E. G. LUENING APPARATUS FOR THE PRODUCTION OF HYDROGEN AND OXYGEN Filed March 21, 1921 2 Sheets-Sheet 2 25542724 625M257, z A-v/ Patented Sept. 29, 1925.

UNITED STATES EUGENE G. LUENING, OF CHICAGO, ILLINOIS.

APPARATUS FOR THE PRODUCTION OF HYDROGEN AND OXYGEN.

Application filed March 21, 1921.

To oZZ whom it may concern:

lie it known that I, Eocene G. LUENING,

a citizen of the United tiitates, residing at Chic go, in the county of Cool; and State of Illinois, have invented certain new and usefui Improvements in apparatus for the production of hydrogen and oxygen for the electrolysis of solutions, particularly applicable to electrolytic apparatus for the generation of hydrogen and oxygen by the decomposition of water, of which the following is a description and specification.

This invention relates to apparatus used for. the electrolysis of solutions, and particularly to apparatus used for the electrolytic production of hydrogen and oxygen gas by the electrolysis of water. Its object is to secure maximum capacity at a satisfactory efficiency in apparatus of this type, and is ap plicable to all existing apparatus for the electrolysis of water to a greater or less degree.

In electrolytic apparatus in general, and particularly that used for the decomposition of water for the production of oxygen and hydrogen, the maximum capacity of any unit or cell of the apparatus has heretofore been based on the laws of electrolysis applicable to the use of particular materials for the electrodes, as, for instance, iron. In determining the capacity and efiiciency of such apparatus, the resistance of the elements to the free passage of electric current, has been the determining factor, based upon the well known law of clectro-chemistry that a specific voltage is required for the decomposition of water. Having determined the required voltage, the economy of a cell is dependent upon a construction which permits gas evolution at a voltage approaching as near as possible to this emperical figure. Thus it may be stated that the efficiency of an electrolytic cell is dependent upon that voltage necessary to produce decomposition of the solution, plus an additional amount above this maximum voltage to overcome the resistance of the various elements and conductors of the apparatus, which includes the resistance offered by the solution itself, the gas film that is present between the solution and the surface of the electrodes, and finally, the resistance in the metallic conductors. The latter resistance, however, is ordi- Serial No. 454,109.

narily disregarded upon the assumption that conductors will be provided which will carry the necessary current without loss. In the development of electrolytic apparatus, the introduction of materials other than iron for the electrodes was found to be advantageous as a method for reducing the oxidation of such material. Thus it became the universal practice to cover the surface of the anodes in contact with the solution with nickel, or metals of like properties, as a protective coating. It was recognized in the design and construction of electrolytic cells in which iron alone was used as the electrode material, that the capacity of such cells as distinguished from the efficiency thereof, was dependent upon the current density; that is, the number of amperes of current per square inch of active electrode surface; that is, surface in contact with the solution. To state it in a different way, the capacity of a cell, which as just mentioned, is dependenton the current density, has direct bearing upon the gas production thereof, but at the same time is distinct from the efficiency of the same cell, this latter term being ordinarily expressed as the ratio of the cubic feet of oxygen produced for every kilowatt-hour of electric current consumed. The standard efiiciency at the present time is approximately 3.65 cubic feet of oxygen and 7.30

cubic feet of hydrogen per kilowatt-hour,

and furthermore, to maintain this efficiency, it has been determined that a cell must opcrate at an approximate voltage of 2.2. Before the utilization of materials other than iron, the limiting quality which determines the capacity, and to some extent the efiiciency of a cell, was the point at which the electrodeposition of iron commenced. This figure was commonly accepted as being approximately at a current density of ten square inches per ampere (or one-tenth ampere per square inch).

However, with the use of materials other than iron, it has not been generally recognized that the current density was changed even tho the mass of the electrode remain iron, and the commonly used protective metal was merely a coating applied to the surface of the iron electrode. Furthermore, the change in the electrode material permitting a greater current density, was not recognized as a basis 01" a different and new principle in determining the elliciency and capacity oi electrolytic cells, in spite of the fact that it was well known in electrochemistry that the electrodeposition of nickel or other metals tool; place at a dillerent current density than deposition of iron in the same solution.

It is therefore the recognition of this principle and its application to the design of electrolytic cells that is the basis for the departure from the ordinary method or construction for such cells, as will hereinafter be described. T he principle above announced and applied to the design and construction of electrolytic cells is primarily based on the heretofore unrecognized ract that in order to obtain maximum economy, and maximum capacity in electrolytic cells, the same must he designed to operate a current density commensurate. with the character of the surface of the i'i'iaterial oi the electrodes, it being evident that a cell cannot be operated at maximum economy or capacity, unless it is designed to carry a current just below that density which involves the electrodeposition of the surface materials 01" the electrodes. 'lhus it may be stated that the proper design of an electrolytic cell, from the standpoint of both economy and capacity, dependent upon the current density at which the electrodeposition of the materials used takes place, and furthermore, that this current density may be confined to that 01 the anode only, because it is at this point that the current enters the solution and discharges its energy thereto in performing the desired decomposition or electrochemical phenomena.

it may he therefore stated that the object of my invention is primarily to increase the gas production of an electrolytic cell, regardless of the efficiency at which it is designed to operate, and without decreasing such e'tliciency or economy of the electrolytic installation.

In order to further bring out the principle already announced and to clearly disclose its application to an electrolytic cell, a preferred construction and design for such cell will now be described, and in connection with the accompanying drawings, in which Figure 1 is a section view of an existing mechanism constructed in accordance with the principles disclosed,

Figure 2 is an end section view talten on line 22 of Figure 1.

1 specific example of an apparatus cinbodying the invention comprises a case 1 containing the cell element 2 consisting of a casting 3 provided with ends 1 and sides 5. The element is suitably supported with its open end downward upon insulator 6. The casting 3 consists of a hon-like structure divided into a number of coinpartn'ients by passage between them. Each electrode is supported from the casting o oy two suspension device; one in each d. The

sn'ialler of these, a rod 15, is merely a pension device insulated "from the t at 16 Figure 1). The other suspension device "on ists of a conductor rod 11' insulated thrnout its length and from the casting- 3 by the insulating paclcing 18. It is provided at its top with electrical connections with bus bars 1919, and has threaded connection at its lower end portion 20 with a contact block 21 01 electrical con ducting); material. This block 21 is attached either by means of rivets 22, or by welding or by other suitable means to the plates 1d1% of each electrode 12 and in such a way that the current for which the cell is designed can be carried without loss to the active surface oi the electrode. So far as this type cell is concerned, the electrodes l2 and 18 are exactly alike except that the cathodes have the conductors 17 at one end while the anodes have them at the opposite end.

In the operation ot this cell, the passage of the electric current trom one electrode; namely, the anode 12, to the adjacent electrode, or cathode 13, thru the intervening diaphragm 8, decomposes the water surrounding? the electrodes into hydrogen and oxygen as previously etplained. @as bubbles term on the outside surface of the plates 14 and rise to the surface of the vater and are collected in the chambers at the upper portions of the case 2, and from thence conducted to the gas reservoirs 2-)i23 communicating with the chambers thru pipes 241 524.

The structure herein described may be said to be typical of an electrolytic cell, so tar as the general arrangement and t ispositi n oi the lQ;"lQ]liS is concernec. The new heretofor unrecognized principle of wlcctrolytic ccl design, however, is based on he relative current carrying capacity of 1 concuctors leading to the electrodes, and the current density or the electrodes themselves. The current carrying capacity of the conductors, and this refers to the bus bars 19, the coinuictors 1?, and Finally the blocks 21., is determined to be tln i which will permit the tree passage of current to the slip 11b 7 than the current density necessdr j 1e electrode deposition the particnar electrode material used in the particular dilution used "therefore, in conipotin which the size ot the conductors is based there millt be taken into consider: ""1 the electro e ar a: that is ti at sat-lace the metal to be used ill the c billowing the CH1" t dens ty tor the electrodeposition ff erial, the probien'r resolc ing s conductor to the electrode iqdensi then that neceor the electrodepost'on oi the matethns arrived at the proper isions oi the conductors deliver tie proper enrvent snipe it reznains a mattor of choice as to the shape of the conductor, and particularly that of the bloclc 21, which tor electrical reasons are pre'terably elonlonp 'itndinally ot the plat -14, in order to promote nniit'orni current distribntion, The wedge shaped blocl: of Figure l considered a satisitactorr shape tor the ,enson that it otl'ers niaiih'nnin current carrycapacily with least amount cit materiah t lo the exact shape is of no particular cement in obtaining the desired results.

The particular adwintages which 'lol ew troni the structure herein discloseth and based on the electi'o-cheinical prii'iciple here in annonnceth is the tly increased prodncti on that may be obtained, regardless of the 1 articular cilicicncy at which the apparates-1 op states, at which it is designed to operate in other words without incneasin5;- oz catering the sire or general structure, it

no i to llltFt; the

gas production moat inert cost of opera llOll or ltfllfltlf ecoi'ioiny. Tlh'is :tact is oi? great in le lien 5101' oil electrolytic inas already in existence whereby by ign ng; 0t certain elen'ienls to-wit:

conductor, it is possible to t l *liltl even more "han double the gas prot Anion without otherwise altering the other 'iactors enteijii'ig into the operation ot a sen unit.

the

ll bat l. (lair-n theri-rtorzn in the an! oil elem" (it 1 1st x in trode having vertica spaced apart plates, a conductor leading to the top thereof and an intervening connecting block of current capacity about equal to the current ca the {late1 fccm'ed on the inside t plate o. la a cell of the class described, a: erode having vertical spaced apart p current staying in lber leadinand connecting device" t lying member and attached o \r-rticn lines extend; ol. the plat l 4. ln a cell o'l ll having spaced spar J side dnctor leadin to th as t connecting bio-cl: iorizontal length attached to the "(.iiltllltftfil and to an interior wall oil the el 5. f 1 a cell of the cl described. trode having spaced apart side w dnctor leading to the upper end t 2 a connecting block of gre Ycrticr horizontal length the Yvldtll of the block being substantially lest than the transverse width 01 the side plates, attached to the conductor and to an interior wall of the elec trode.

6. in a device of the class described, a hollow electrode comprising parallel side walls and connecting end parts, open top and botton'i for the passage of liquid from top to bottom ot the electrode large cepacity electric conductor entering one end ot the electrode from the top and wedge shaped conductor connector attached to said conductor pert, with the base oil the wedge at the top ol the electrode and its point at the end ot the electrode and near the bottom there t, and means for electrically connect ing said wedge blocl: to the interior of the wall ot the electrode.

1 ltn a device of the class described, a hell- Z he low electrod con'mrisine' carallcl side walls .r f i and connecting; end parts open top and betem for the passage of liquid from top to bottom of the electrode a large capacity electric conductor entering one end of the electrode tern the top and a wedge shaped conductor connector attached. to said conductor part, with the base ot the edge at the top of the electrode and its point at the end of the electrode and near the bottom thereofi and welding 1n ans for electrically connecting said wedge block to the interior or? the well (it the electrode 8. its an article eli' toannntacture an electrode consisting of two parsllel separated it. ..l pl s elf relative large area spaced apert at their ends tl'ierc being interposed between said pletes at one end of the electrode a downwmdl pointed wedee shaped block welded. thereto, said wedge being adapted at its u per end for electric connection with a current ratifying rod oi very substantial capacity.

9. In a cell, an electrode having spaced apart plates, a conductor, and a connecting bloc-l; electrically connecting the plates and conductor, said block having substantially the current carrying capacity of the entire plates where joined therewith.

10. In a cell, an electrode having spaced apart plat-cs, a conductor, and a connecting block disposed between and engaging; the inner faces of the plates and electrically connecting the plates and conductor, said block having substantially the current carrying capacity of the entire plates where joined therewith.

ii. In a. cell, an electrode having upright spaced apart walls, a conchichn' and :2. connecting block electrically connecting said conductor and walls and having the upright clin'icnsion of its place of engagement with said walls in excess of the horizontal dimension of its place of engagement with said walls.

12. In cell, an electrode having upright spaced apart plates, a conductor, and a connecting block disposed between and engaging the inner faces of the plates, and electrically connecting said conductor and plates and having the upright dimension of its place of engagement with said plates in eX- cess of the horizontal dimension oi its place oi engagement with said plates.

In witness whereof, I hereunto subscribe my name this 17th day of Marcln A. D, 1921.

EUGENE G. LUENING. 

